Welcome to space - and bit of a problem

Hours after a new two-man crew arrived at the international space station, one of the gyroscopes that keeps the orbiting outpost steady failed, and NASA said a spacewalk would be needed to fix it.

The problem stemmed from a failure in a circuit-breaker on one of the station's external girders, said the space station's manager, Mike Suffredini.

Because the box that holds the circuit-breaker is outside the station a spacewalk would probably be required, Mr Suffredini said.

He stressed that it was not "a safety issue". It would take several weeks to determine when to schedule the spacewalk.

Two gyroscopes were still functioning, and that was enough to stabilise the station, Mr Suffredini said.

If one of the remaining gyroscopes failed, the station would rely on thrusters to keep it steady. Mr Suffredini estimated there was enough propellant to keep the thrusters going for six months and possibly for a year.

The spacewalk would involve two crew. It would not take place while the old and new crews were aboard the station for an 11-day overlap, he said.

A spacewalk could add eight to 10 days to that overlap period. This would change an expected daylight landing of the Soyuz spacecraft to a night landing, which would make recovery more difficult.

The Russian commander, Gennady Padalka, and a US flight engineer, Michael Fincke, will spend six months in space. A Dutchman, Andre Kuipers, of the European Space Agency, is accompanying them to conduct experiments.

A Russian cosmonaut, Alexander Kaleri, and NASA's Michael Foale, who have been aboard the station for six months, will return to Earth.

A spacewalk to fix the circuit-breaker would be the second time both crew members would be outside the space station, leaving no one inside. The first such walk took place in February.